What is 3:2 Aspect Ratio?
3:2 gives 3 units of width for every 2 of height - a decimal of 1.5, slightly wider than 4:3 and slightly squarer than 16:9. It is the shape of the 35 mm film frame that dominated a century of photography, and digital SLRs inherited it: full-frame and APS-C sensors record native 3:2 images, typically 6000×4000 on a 24 megapixel camera. The standard 4×6 inch print is exactly 3:2, which is why DSLR photos print on 4×6 with no crop - and why moving to other print sizes or social formats requires trimming.
Common Uses for 3:2 Aspect Ratio
- Native output of full-frame and APS-C cameras
- 4×6 inch photo prints with zero cropping
- Postcards and classic photo albums
- Landscape photography that later crops to 16:9 or 1:1
Why 3:2 survived a century
Oskar Barnack's original Leica used 35 mm cine film run horizontally, giving an 36×24 mm frame - exactly 3:2. The shape balances width against printability: wide enough for landscape composition, close enough to standard paper sheets that prints waste little. When sensors replaced film, keeping 3:2 preserved lens design expectations and the entire print ecosystem, which is why it persists even as screens went 16:9.